Aneurysmal disease: the abdominal aorta.

Abdominal aortic aneurysm (AAA) is one of the leading causes of death in the United States. Approximately 80% of AAAs occur in the infrarenal abdominal aorta. Most are caused by a degenerative process in the aortic wall, and smoking is the risk factor most strongly associated with AAA. Contrast-enhanced computed tomography is the most reliable imaging modality. Open repair is more invasive initially but more durable, whereas endovascular aneurysm repair is less invasive but less durable. Since degradation of the aorta progresses with age, continuous follow-up after aneurysmal repair improves the long-term outcome.